This invention relates to liquid-gas separators and more particularly to downhole liquid-gas separators used in conjunction with submergible pumps.
Liquid-gas separators are used downhole in oil-producing wells to separate gas from crude oil before the oil enters the downhole pump. See, for example, U.S. Pat. Nos. 2,104,339 and 2,969,742, both assigned to the same assignee as the present invention. Any gas present in the oil supplied to the pump tends to reduce the volumetric efficiency of the pump. Thus an effective liquid-gas separator enables the pumping of more oil. The present invention is directed to an improved liquid-gas separator and employs a unique fine mesh screen structure to provide better separation of gas from liquid than has been possible with comparable separators known heretofore.
The prior art is replete with separators or filters employing screens or other porous structures. U.S. Pat. No. 3,933,448 discloses a device employing a convoluted screen partition which passes liquid, but not gas. U.S. Pat. No. 3,394,533 discloses a device employing a conical screen (with its axis horizontal) which passes gas but not liquid. U.S. Pat. No. 3,893,925 discloses a device employing an upright perforated fluted conical structure for separating oil from water. See also U.S. Pat. Nos. 4,050,237; 3,386,230; 3,413,778; 3,492,793; 2,823,760; 3,664,093; 3,892,547; 1,711,779; 3,448,862; 621,998; 1,071,328; 2,096,484; 2,170,074; 2,191,052; 2,717,148; 2,749,265; and 3,159,310. Despite the proliferation of prior art, a need has remained for a superior device for separating liquid such as crude oil from gas in a downhole environment.